Evaluate the effectiveness of vaccination and screening programmes

Vaccination and screening programs have been, overall, very successful in improving the human condition. For example, smallpox, which was once a dreaded scourge that killed millions, has been completely eliminated by aggressive immunization programs worldwide; the World Health Organization declared the disease extinct in 1979. Similarly, immunizations for measles and rubella have greatly limited those diseases, along with their attendant side effects and complications, in developed countries. Influenza vaccinations are commonplace, and are important in protecting those who are more vulnerable to the flu, particularly the young and the elderly, as well as those who work with vulnerable populations.

Even animal vaccination programs have helped humans; vaccinating pets and domestic livestock against rabies has greatly limited the extent and spread of that fatal disease. This has been so successful that in some areas bait cubes containing rabies immunization are routinely dropped in woodland areas in an attempt to protect wild animals populations from succumbing to rabies.